In the age of cloud computing and big data, requirements on storage performance are increasingly high. Therefore, development and application of software-defined storage (SDS) become an inevitable trend. A core of an SDS technology is to put storage-related control operations into external software relative to physical storage hardware. As a part of an operating system (OS) or a management program (for example, hypervisor), the software runs on a NFS server. The SDS technology abstracts software from hardware storage to form a shared pool that is not limited by a physical system, such that storage access can be more flexibly controlled.
An SDS technology used by a virtualization platform includes a block-level fiber channel (FC) technology, and Internet Small Computer Systems Interface (iSCSI) storage, or file-level NFS storage. A user may select an appropriate storage protocol according to different production environments and test environments, and performance and reliability requirements and other requirements.
In an NFS storage system, a client needs to identify a file using a hierarchical structure of a NFS server, so as to perform a subsequent operation. Generally, the NFS server allocates a unique file handle to each file, and uses the file handle as an identifier. However, the file handle is not global, and each NFS server maintains its own NFS file handle (NFS FH), mount list, and mapping relationship between the NFS FH and a file system handle (FSH) at a back end.
When a virtual machine migrates, a service on the virtual machine is not disabled. Therefore, when performing data communication with a new NFS server, the virtual machine still uses an old context. As a result, the new NFS server cannot identify the context, thereby causing a service interruption. Alternatively, if the virtual machine first disconnects a connection established between the virtual machine and a previous NFS server previously, then migrates, and then establishes a connection to the new NFS server, the process is relatively time-consuming, does not meet a requirement for service perception-free during virtual machine migration, and may also cause a service interruption.